Evolutionary Biologists Think They Found Where the Female Orgasm Came From

As you may have discovered in your own research, the female orgasm is quite different from the male orgasm — not only in form, but also in function. While the male orgasm is necessary for reproduction, the female orgasm is not. According to new evolutionary biology research, the reasons why can be seen in more evolutionarily simple mammals.

Consider the cat or the rabbit. As researchers Mihaela Pavličev of the University of Cincinnati and Günter Wagner of Yale Medical School observe in a new paper in Experimental Zoology, these simpler mammals have “male-induced ovulation,” meaning that an egg only gets released during during sex. These animals also experience a sort of sexual climax, zoologists think, and when they do, they don’t just ovulate, they also release prolactin, a hormone associated with milk production. For female humans, prolactin also spikes after orgasm — other research indicates that the more prolactin that gets released, the bigger the orgasm was and the greater the sexual satisfaction. For simpler mammals, the female orgasm was (and is) crucial for making babies. But for humans, the process that used to usher along the egg no longer does.

“Female orgasm is an evolutionary vestige like the appendix,” Wagner, the Yale researcher, told Shanoor Seervai at STAT. “It is not clear if it has a function beyond psychological bonding between partners.” It’s like music, he explained: one of the finer things in life that elevates humanity beyond more savage beasts. “The value of something the human body is capable of does not have to be functional,” he argued.

But I’d be inclined to disagree, at least to a point. Even if orgasm is merely promoting the psychological bonding of partners, that’s quite adaptive, since research indicates that people who are in long-term relationships report higher levels of subjective well-being than people who date casually or not at all. From the evolutionary perspective that you should be passing on your genes so that they may flourish, having strong, orgasm-encouraged bonds with someone would actually assist in child-rearing, since the offspring would be arriving into a more stable family situation. The female orgasm might be vestigial, but compared to sinuses or goose bumps, it helps human life way more. It just happens to be more relational than strictly reproductive.